No, you haven't to jaibreak. It will work even on stock non-jailbroken devices.

Thanks, eureka. I've uninstalled jailbreak for KT, and add new fonts following the instruction. The problem is I still got "Your Kindle Needs Repair" after restart. I can get into the system by plugging it into my PC. But all fonts are gone in the Aa menu. Seems this method does not works for me.

Hai Friends, I've just registered here to know how to install KT FontHack.

I've a Kindle Touch (v.5.1.2) and jailbreak-ed it yesterday according to steps here.

After that I've downloaded the KTFontHack 1.3.2 available at here.
Now I'm unable to follow the steps mentioned here for KTFontHack 1.3.2.

In that readme.txt file, at step
1-b. it says "Copy the update_fonthack-*_install.bin file to the root directory of your Kindle.", problem is I can't find that "update_fonthack-*_install.bin" anywhere in the "zip" file I downloaded earlier.

Hai Friends, I've just registered here to know how to install KT FontHack.

I've a Kindle Touch (v.5.1.2) and jailbreak-ed it yesterday according to steps here.

After that I've downloaded the KTFontHack 1.3.2 available at here.
Now I'm unable to follow the steps mentioned here for KTFontHack 1.3.2.

In that readme.txt file, at step
1-b. it says "Copy the update_fonthack-*_install.bin file to the root directory of your Kindle.", problem is I can't find that "update_fonthack-*_install.bin" anywhere in the "zip" file I downloaded earlier.

Any help would be greatly appreciated.

You downloaded the source code instead of the binary distribution.
See the first post of this thread for binary downloads.

Sorry but i`m a noob and don`t works for me.
I followed readme steps 1 by 1. I have KT5 with 5.1.2 firmware. I have jailbrake and gui launcher. I installed all update files (fonthack 1.3.2, kindlet jailbreak and combined dev certs) but do not happens anything! Before install fonthack in Kindle root menu apear two folder fonthack (empty) and developer (another 3 folder like metadata etc.). Thank you in advance!

New $69 kindle uses the same display as the Touch - Paperwhite is higher resolution. But the $69 is advertised as: "New darker, hand-tuned fonts for easier reading"
I wonder what font is the new default?

Hey guys, sorry for lame questions but... I jailbroke my KT, updated it with kindlet jailbreak, updated with fonthack, put some fonts, initialized every single one of them, rebuilt font cache and then restarted framework (I also restarted KT at least twice)... and I'm not sure how to use them properly. At first I thought that I'd put fonts in the wrong folder because there are two font hacks, one in the root directory and the other I don't really remember :P anyway I put my fonts in the first one and I guess it worked since the fonthack initialized them, right?
So, from what I understood, if I want to change fonts I have to enter Font Hack, choose desired font, click serif, sans serif, condensed or monospace. Then whlie reading I go to 'Aa' and pick regular, condensed or sans serif. And everytime I change fonts (and reset KT) not only the text is in different font but menus and book list as well.

So my questions are:
- what is monospace?
- can i switch between regular font and bold one? (I got some mobi books in bold)
- is there a way to change just text font (inside the book) and not the menus & book list

if you only change the condensed font with fonthack no menus or other things are changed in the gui.
So change condensed to your favorite font (I am doing the same).

- Monospace is a font where the "i" letter is as wide as the "W" letter e.g. Courier font.
- bold is not a font it is a font variant, so switching is not so easy. you have to modify the book source
- read above

ok, I'm starting to lose my mind here... I just can not find the original ones. I can only see the ones I put. People, I'm a blonde guy who just wants his default fonts back... share more detailed tips to do that. Please